In Case You Missed 'Em: Prominent Studies Published in Past Year

MIAMI BEACH – What do the timing of smoking cessation prior to surgery, reliable prediction of postoperative respiratory failure, and biomarkers that point to elevated postoperative myocardial infarction risk have in common? They emerged as some of the most prominent findings published in the past year, according to three experts in hospital medicine.

Dr. Gerald W. Smetana, Dr. Steven L. Cohn, and Dr. Paul J. Grant each selected studies of particular relevance to hospitalists and explained why during a panel presentation at a meeting on perioperative medicine sponsored by the University of Miami:

© milosluz/istockphoto.com

• Preoperative Smoking Cessation. When a patient stops smoking up to 8 weeks before noncardiac surgery, it does not significantly change the total or pulmonary complication rates, according to a systematic literature review (Arch. Intern. Med. 2011;171:983-9).

"Many patients who quit smoking report they feel worse before they feel better," said Dr. Smetana, an attending in the general medicine division at Beth Israel Deaconess Medical Center, Boston.

Increased cough and sputum production are common right after quitting, he said. "This could be a plausible mechanism to explain why recent quitters might be at increased risk for postoperative pulmonary complications."

However, there was no statistically significant difference in total complications (relative risk of 0.78 for recent quitters, compared with a reference value of 1.0 for current smokers) in the nine eligible studies with 889 participants. Five of the trials assessed pulmonary complications, and found that recent quitters had a nonsignificant increased risk (RR, 1.18) compared with patients who continued to smoke.

Until there is consensus based on large randomized trials, stopping smoking before surgery can be considered safe, said Dr. Smetana, who is also on the medicine faculty at Harvard Medical School. In addition, longer periods of cessation are likely better than shorter ones. He added that despite the lack of a significant finding, it is still worthwhile to counsel patients because any time before surgery is a still a teachable moment for smoking cessation.

• Predicting Postoperative Pulmonary Failure. Type of procedure, emergency surgery, poor dependent functional status, sepsis, and higher American Society of Anesthesiologists classification were the five independent preoperative factors that significantly predicted postoperative respiratory failure in a multicenter database study (Chest 2011;140:1207-15).

The study included 211,410 participants undergoing all types of surgery. Mortality was 26% among those with postoperative respiratory failure, compared with 1% for unaffected patients. "This shows how important pulmonary complications can be," Dr. Smetana said.

The researchers incorporated these five predictors into a surgical risk calculator that is downloadable for free.

Dr. Smetana said, "It is a nice tool that ... helps to stratify patients. It makes a difference in identifying which patients for which you will pull out all the stops."

• Preoperative Peptide Gauges Risk. Although multiple researchers have looked at preoperative B-type natriuretic peptide (BNP) as a predictor of postoperative cardiac events or death, there remain "a lot of unknowns for BNP at this point," said Dr. Cohn, director of the University of Miami Hospital Medical Consultation Service and professor of medicine at the University of Miami.

A recent meta-analysis may shed some light on the predictive value of BNP (J. Am. Coll. Cardiol. 2011;58:522-9). Investigators assessed five BNP studies with 632 patients to determine cutoff values for screening (high sensitivity) and diagnosis (high specificity), and an optimal value that combines both.

The researchers found that patients with BNP above the optimal cutoff point of 116 pg/mL had a significantly elevated risk for the composite outcome of nonfatal myocardial infarction or cardiovascular death (unadjusted odds ratio, 7.36). Compared with use of the Revised Cardiac Risk Index, the optimal BNP cutoff classification improved risk prediction by 58%. This means some patients moved to a more accurate ranking among the low-, intermediate- and high-risk categories, Dr. Cohn said.

• Troponin and Postoperative MI Risk. Myocardial infarction is the most common major, perioperative vascular complication, so investigators continue to search for an accurate way to identify high-risk patients. Some propose elevated serum levels of the protein troponin as a predictor, Dr. Cohn said, but the question remains: Would it change patient management and improve outcomes?

Researchers found that increased troponin after noncardiac surgery did in fact independently predict postoperative MI mortality in a meta-analysis (Anesthesiology 2011;114:796-806).

Elevated levels significantly predicted increased risk in the 14 studies with 3,318 patients overall (OR, 3.4). However, prediction within the first year was higher (OR, 6.7) compared with studies that measured troponin more than 12 months out (OR, 1.8).

These findings could have implications for practice, because the majority of perioperative MIs are asymptomatic, Dr. Cohn said. "Maybe we should, as the authors suggest, recommend routine troponins after high-risk surgery."

More frequent vital-sign monitoring; transfer to a unit with additional monitoring; and/or screening for hypoxia and anemia could be implemented in patients identified as high risk, Dr. Cohn said. Optimization of intravascular volume and initiation of cardiac medications are additional strategies. Also, closely monitored patients who experience an MI potentially could be transferred for cardiac catheterization or revascularization more quickly.

"It is thought provoking that we can change the management," Dr. Cohn said.

• HF, AF, and Cardiovascular Risk. Heart failure and atrial fibrillation should factor more prominently into cardiovascular risk stratification prior to noncardiac surgery, according to a population-based cohort study of more than 38,000 consecutive patients (Circulation 2011:124:289-96).

"There are many cardiovascular risk stratification tools available with quite a bit of variation. Coronary artery disease [CAD] is typically weighted heavily on most models," said Dr. Grant, director of perioperative and consultative medicine and member of the medicine faculty at the University of Michigan in Ann Arbor.

However, researchers found that ischemic and nonischemic heart failure and atrial fibrillation were more commonly associated with 30-day mortality and readmission rates than CAD in this large cohort, Dr. Grant said. The authors concluded that these risk factors are likely underestimated in current prediction models.

• Liberal vs. Conservative Blood Transfusion. "The hemoglobin level at which we decide to transfuse patients after surgery is controversial," Dr. Grant said, "and has not been adequately studied to date. Great variations in practice exist."

A randomized controlled trial of 2,016 hip fracture surgery patients found no significant difference between liberal and conservative postoperative blood transfusion policies in terms of mortality or ability to walk independently at 60 days for patients at high cardiovascular risk (N. Engl. J. Med. 2011;365:2453-62).

The liberal policy allowed transfusions to maintain hemoglobin at 10 g/dL. In contrast, patients randomized to a conservative approach could only be transfused if they had symptoms of anemia or at the physician’s discretion once hemoglobin was below 8 g/dL.

"Implications for practice, from my point of view, include some more evidence that maybe using more of a restrictive transfusion practice may be reasonable, including for higher-risk populations," Dr. Grant said. However, "red-cell transfusion practices still need to be individualized for your perioperative patient."

Dr. Smetana, Dr. Cohn, and Dr. Grant had no relevant financial disclosures.

MIAMI BEACH – What do the timing of smoking cessation prior to surgery, reliable prediction of postoperative respiratory failure, and biomarkers that point to elevated postoperative myocardial infarction risk have in common? They emerged as some of the most prominent findings published in the past year, according to three experts in hospital medicine.

Dr. Gerald W. Smetana, Dr. Steven L. Cohn, and Dr. Paul J. Grant each selected studies of particular relevance to hospitalists and explained why during a panel presentation at a meeting on perioperative medicine sponsored by the University of Miami:

© milosluz/istockphoto.com

• Preoperative Smoking Cessation. When a patient stops smoking up to 8 weeks before noncardiac surgery, it does not significantly change the total or pulmonary complication rates, according to a systematic literature review (Arch. Intern. Med. 2011;171:983-9).

"Many patients who quit smoking report they feel worse before they feel better," said Dr. Smetana, an attending in the general medicine division at Beth Israel Deaconess Medical Center, Boston.

Increased cough and sputum production are common right after quitting, he said. "This could be a plausible mechanism to explain why recent quitters might be at increased risk for postoperative pulmonary complications."

However, there was no statistically significant difference in total complications (relative risk of 0.78 for recent quitters, compared with a reference value of 1.0 for current smokers) in the nine eligible studies with 889 participants. Five of the trials assessed pulmonary complications, and found that recent quitters had a nonsignificant increased risk (RR, 1.18) compared with patients who continued to smoke.

Until there is consensus based on large randomized trials, stopping smoking before surgery can be considered safe, said Dr. Smetana, who is also on the medicine faculty at Harvard Medical School. In addition, longer periods of cessation are likely better than shorter ones. He added that despite the lack of a significant finding, it is still worthwhile to counsel patients because any time before surgery is a still a teachable moment for smoking cessation.

• Predicting Postoperative Pulmonary Failure. Type of procedure, emergency surgery, poor dependent functional status, sepsis, and higher American Society of Anesthesiologists classification were the five independent preoperative factors that significantly predicted postoperative respiratory failure in a multicenter database study (Chest 2011;140:1207-15).

The study included 211,410 participants undergoing all types of surgery. Mortality was 26% among those with postoperative respiratory failure, compared with 1% for unaffected patients. "This shows how important pulmonary complications can be," Dr. Smetana said.

The researchers incorporated these five predictors into a surgical risk calculator that is downloadable for free.

Dr. Smetana said, "It is a nice tool that ... helps to stratify patients. It makes a difference in identifying which patients for which you will pull out all the stops."

• Preoperative Peptide Gauges Risk. Although multiple researchers have looked at preoperative B-type natriuretic peptide (BNP) as a predictor of postoperative cardiac events or death, there remain "a lot of unknowns for BNP at this point," said Dr. Cohn, director of the University of Miami Hospital Medical Consultation Service and professor of medicine at the University of Miami.

A recent meta-analysis may shed some light on the predictive value of BNP (J. Am. Coll. Cardiol. 2011;58:522-9). Investigators assessed five BNP studies with 632 patients to determine cutoff values for screening (high sensitivity) and diagnosis (high specificity), and an optimal value that combines both.

The researchers found that patients with BNP above the optimal cutoff point of 116 pg/mL had a significantly elevated risk for the composite outcome of nonfatal myocardial infarction or cardiovascular death (unadjusted odds ratio, 7.36). Compared with use of the Revised Cardiac Risk Index, the optimal BNP cutoff classification improved risk prediction by 58%. This means some patients moved to a more accurate ranking among the low-, intermediate- and high-risk categories, Dr. Cohn said.

• Troponin and Postoperative MI Risk. Myocardial infarction is the most common major, perioperative vascular complication, so investigators continue to search for an accurate way to identify high-risk patients. Some propose elevated serum levels of the protein troponin as a predictor, Dr. Cohn said, but the question remains: Would it change patient management and improve outcomes?

Researchers found that increased troponin after noncardiac surgery did in fact independently predict postoperative MI mortality in a meta-analysis (Anesthesiology 2011;114:796-806).

Elevated levels significantly predicted increased risk in the 14 studies with 3,318 patients overall (OR, 3.4). However, prediction within the first year was higher (OR, 6.7) compared with studies that measured troponin more than 12 months out (OR, 1.8).

These findings could have implications for practice, because the majority of perioperative MIs are asymptomatic, Dr. Cohn said. "Maybe we should, as the authors suggest, recommend routine troponins after high-risk surgery."

More frequent vital-sign monitoring; transfer to a unit with additional monitoring; and/or screening for hypoxia and anemia could be implemented in patients identified as high risk, Dr. Cohn said. Optimization of intravascular volume and initiation of cardiac medications are additional strategies. Also, closely monitored patients who experience an MI potentially could be transferred for cardiac catheterization or revascularization more quickly.

"It is thought provoking that we can change the management," Dr. Cohn said.

• HF, AF, and Cardiovascular Risk. Heart failure and atrial fibrillation should factor more prominently into cardiovascular risk stratification prior to noncardiac surgery, according to a population-based cohort study of more than 38,000 consecutive patients (Circulation 2011:124:289-96).

"There are many cardiovascular risk stratification tools available with quite a bit of variation. Coronary artery disease [CAD] is typically weighted heavily on most models," said Dr. Grant, director of perioperative and consultative medicine and member of the medicine faculty at the University of Michigan in Ann Arbor.

However, researchers found that ischemic and nonischemic heart failure and atrial fibrillation were more commonly associated with 30-day mortality and readmission rates than CAD in this large cohort, Dr. Grant said. The authors concluded that these risk factors are likely underestimated in current prediction models.

• Liberal vs. Conservative Blood Transfusion. "The hemoglobin level at which we decide to transfuse patients after surgery is controversial," Dr. Grant said, "and has not been adequately studied to date. Great variations in practice exist."

A randomized controlled trial of 2,016 hip fracture surgery patients found no significant difference between liberal and conservative postoperative blood transfusion policies in terms of mortality or ability to walk independently at 60 days for patients at high cardiovascular risk (N. Engl. J. Med. 2011;365:2453-62).

The liberal policy allowed transfusions to maintain hemoglobin at 10 g/dL. In contrast, patients randomized to a conservative approach could only be transfused if they had symptoms of anemia or at the physician’s discretion once hemoglobin was below 8 g/dL.

"Implications for practice, from my point of view, include some more evidence that maybe using more of a restrictive transfusion practice may be reasonable, including for higher-risk populations," Dr. Grant said. However, "red-cell transfusion practices still need to be individualized for your perioperative patient."

Dr. Smetana, Dr. Cohn, and Dr. Grant had no relevant financial disclosures.

MIAMI BEACH – What do the timing of smoking cessation prior to surgery, reliable prediction of postoperative respiratory failure, and biomarkers that point to elevated postoperative myocardial infarction risk have in common? They emerged as some of the most prominent findings published in the past year, according to three experts in hospital medicine.

Dr. Gerald W. Smetana, Dr. Steven L. Cohn, and Dr. Paul J. Grant each selected studies of particular relevance to hospitalists and explained why during a panel presentation at a meeting on perioperative medicine sponsored by the University of Miami:

© milosluz/istockphoto.com

• Preoperative Smoking Cessation. When a patient stops smoking up to 8 weeks before noncardiac surgery, it does not significantly change the total or pulmonary complication rates, according to a systematic literature review (Arch. Intern. Med. 2011;171:983-9).

"Many patients who quit smoking report they feel worse before they feel better," said Dr. Smetana, an attending in the general medicine division at Beth Israel Deaconess Medical Center, Boston.

Increased cough and sputum production are common right after quitting, he said. "This could be a plausible mechanism to explain why recent quitters might be at increased risk for postoperative pulmonary complications."

However, there was no statistically significant difference in total complications (relative risk of 0.78 for recent quitters, compared with a reference value of 1.0 for current smokers) in the nine eligible studies with 889 participants. Five of the trials assessed pulmonary complications, and found that recent quitters had a nonsignificant increased risk (RR, 1.18) compared with patients who continued to smoke.

Until there is consensus based on large randomized trials, stopping smoking before surgery can be considered safe, said Dr. Smetana, who is also on the medicine faculty at Harvard Medical School. In addition, longer periods of cessation are likely better than shorter ones. He added that despite the lack of a significant finding, it is still worthwhile to counsel patients because any time before surgery is a still a teachable moment for smoking cessation.

• Predicting Postoperative Pulmonary Failure. Type of procedure, emergency surgery, poor dependent functional status, sepsis, and higher American Society of Anesthesiologists classification were the five independent preoperative factors that significantly predicted postoperative respiratory failure in a multicenter database study (Chest 2011;140:1207-15).

The study included 211,410 participants undergoing all types of surgery. Mortality was 26% among those with postoperative respiratory failure, compared with 1% for unaffected patients. "This shows how important pulmonary complications can be," Dr. Smetana said.

The researchers incorporated these five predictors into a surgical risk calculator that is downloadable for free.

Dr. Smetana said, "It is a nice tool that ... helps to stratify patients. It makes a difference in identifying which patients for which you will pull out all the stops."

• Preoperative Peptide Gauges Risk. Although multiple researchers have looked at preoperative B-type natriuretic peptide (BNP) as a predictor of postoperative cardiac events or death, there remain "a lot of unknowns for BNP at this point," said Dr. Cohn, director of the University of Miami Hospital Medical Consultation Service and professor of medicine at the University of Miami.

A recent meta-analysis may shed some light on the predictive value of BNP (J. Am. Coll. Cardiol. 2011;58:522-9). Investigators assessed five BNP studies with 632 patients to determine cutoff values for screening (high sensitivity) and diagnosis (high specificity), and an optimal value that combines both.

The researchers found that patients with BNP above the optimal cutoff point of 116 pg/mL had a significantly elevated risk for the composite outcome of nonfatal myocardial infarction or cardiovascular death (unadjusted odds ratio, 7.36). Compared with use of the Revised Cardiac Risk Index, the optimal BNP cutoff classification improved risk prediction by 58%. This means some patients moved to a more accurate ranking among the low-, intermediate- and high-risk categories, Dr. Cohn said.

• Troponin and Postoperative MI Risk. Myocardial infarction is the most common major, perioperative vascular complication, so investigators continue to search for an accurate way to identify high-risk patients. Some propose elevated serum levels of the protein troponin as a predictor, Dr. Cohn said, but the question remains: Would it change patient management and improve outcomes?

Researchers found that increased troponin after noncardiac surgery did in fact independently predict postoperative MI mortality in a meta-analysis (Anesthesiology 2011;114:796-806).

Elevated levels significantly predicted increased risk in the 14 studies with 3,318 patients overall (OR, 3.4). However, prediction within the first year was higher (OR, 6.7) compared with studies that measured troponin more than 12 months out (OR, 1.8).

These findings could have implications for practice, because the majority of perioperative MIs are asymptomatic, Dr. Cohn said. "Maybe we should, as the authors suggest, recommend routine troponins after high-risk surgery."

More frequent vital-sign monitoring; transfer to a unit with additional monitoring; and/or screening for hypoxia and anemia could be implemented in patients identified as high risk, Dr. Cohn said. Optimization of intravascular volume and initiation of cardiac medications are additional strategies. Also, closely monitored patients who experience an MI potentially could be transferred for cardiac catheterization or revascularization more quickly.

"It is thought provoking that we can change the management," Dr. Cohn said.

• HF, AF, and Cardiovascular Risk. Heart failure and atrial fibrillation should factor more prominently into cardiovascular risk stratification prior to noncardiac surgery, according to a population-based cohort study of more than 38,000 consecutive patients (Circulation 2011:124:289-96).

"There are many cardiovascular risk stratification tools available with quite a bit of variation. Coronary artery disease [CAD] is typically weighted heavily on most models," said Dr. Grant, director of perioperative and consultative medicine and member of the medicine faculty at the University of Michigan in Ann Arbor.

However, researchers found that ischemic and nonischemic heart failure and atrial fibrillation were more commonly associated with 30-day mortality and readmission rates than CAD in this large cohort, Dr. Grant said. The authors concluded that these risk factors are likely underestimated in current prediction models.

• Liberal vs. Conservative Blood Transfusion. "The hemoglobin level at which we decide to transfuse patients after surgery is controversial," Dr. Grant said, "and has not been adequately studied to date. Great variations in practice exist."

A randomized controlled trial of 2,016 hip fracture surgery patients found no significant difference between liberal and conservative postoperative blood transfusion policies in terms of mortality or ability to walk independently at 60 days for patients at high cardiovascular risk (N. Engl. J. Med. 2011;365:2453-62).

The liberal policy allowed transfusions to maintain hemoglobin at 10 g/dL. In contrast, patients randomized to a conservative approach could only be transfused if they had symptoms of anemia or at the physician’s discretion once hemoglobin was below 8 g/dL.

"Implications for practice, from my point of view, include some more evidence that maybe using more of a restrictive transfusion practice may be reasonable, including for higher-risk populations," Dr. Grant said. However, "red-cell transfusion practices still need to be individualized for your perioperative patient."

Dr. Smetana, Dr. Cohn, and Dr. Grant had no relevant financial disclosures.